Reaction of Building Stones with Atmospheric Pollutants | |
| We have investigated the reaction of building stones with sulfur dioxide-containing atmosphere. This is a joint program with the Materials Research Program of the National Center for Preservation Training and Technology of the National Park Service. | |
| Two building stones are currently under investigation: | |
| The Cretaceous Walnut Formation limestone quarried from near Austin TX. This building stone is used prominently at the University of Houston. | |
| A volcanic rock from which the Catedral de Mexico, Mexico City is built. | |
| The building stones were imaged using electron microprobe back-scattered and x-ray imaging. They were then exposed to an atmosphere containing ~100 ppm sulfur dioxide with 75% humidity at 25ºC for two weeks. This was performed at the NCPTT through the offices of Dr. Mary Striegel. The stones were then re-imaged in order to find which regions of the stones were preferentially altered by the sulfur dioxide and whether sulfates were precipitated in the samples. | |
| Research conducted by Javier Pruneda, senior undergraduate Dept. of Chemistry, U. of H. | |